<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 3//EN">
<HTML><HEAD>
		<TITLE>User's Guide - Glossary</TITLE>
		<META HTTP-EQUIV="keywords" CONTENT="GRAPHICS VISUALIZATION VISUAL PROGRAM DATA
MINING">
	<meta http-equiv="content-type" content="text/html;charset=ISO-8859-1">
</HEAD><BODY BGCOLOR="#FFFFFF" link="#00004b" vlink="#4b004b">
		<TABLE width=510 border=0 cellpadding=0 cellspacing=0>
			<TR>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=80 HEIGHT=1></TD>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=49 HEIGHT=1></TD>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=24 HEIGHT=1></TD>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=100 HEIGHT=1></TD>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=3 HEIGHT=1></TD>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=127 HEIGHT=1></TD>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=6 HEIGHT=1></TD>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=50 HEIGHT=1></TD>
				<TD><IMG SRC="../images/spacer.gif" WIDTH=71 HEIGHT=1></TD>
			</TR>
			<TR>
				<TD colspan=9><IMG src="../images/flcgh_01.gif" width=510 height=24 border="0" alt="OpenDX - Documentation"></TD>
			</TR>
			<TR>
				<TD colspan=2><A href="../allguide.htm"><IMG src="../images/flcgh_02.gif" width=129 height=25 border="0" alt="Full Contents"></A></TD>
				<TD colspan=3><A href="../qikguide.htm"><IMG src="../images/flcgh_03.gif" width=127 height=25 border="0" alt="QuickStart Guide"></A></TD>
				<TD><A href="../usrguide.htm"><B><IMG src="../images/flcgh_04d.gif" width=127 height=25 border="0" alt="User's Guide"></B></A></TD>
				<TD colspan=3><A href="../refguide.htm"><IMG src="../images/flcgh_05.gif" width=127 height=25 border="0" alt="User's Reference"></A></TD>
			</TR>
			<TR>
				<TD><A href="usrgu078.htm"><IMG src="../images/flcgh_06.gif" width=80 height=17 border="0" alt="Previous Page"></A></TD>
				<TD colspan=2><A href="usrgu080.htm"><IMG src="../images/flcgh_07.gif" width=73 height=17 border="0" alt="Next Page"></A></TD>
				<TD><A href="../usrguide.htm"><IMG src="../images/flcgh_08.gif" width=100 height=17 border="0" alt="Table of Contents"></A></TD>
				<TD colspan=3><A href="usrgu073.htm"><IMG src="../images/flcgh_09.gif" width=136 height=17 border="0" alt="Partial Table of Contents"></A></TD>
				<TD><A href="usrgu080.htm"><IMG src="../images/flcgh_10.gif" width=50 height=17 border="0" alt="Index"></A></TD>
				<TD><A href="../srchindx.htm"><IMG SRC="../images/flcgh_11.gif" width=71 height=17 border="0" alt="Search"></A></TD>
			</TR>
		</TABLE>
		<H2><A NAME="HDRUSRGLOS" ></A>Chapter 12. Glossary</H2>
		<P>
Some of the definitions in this glossary are taken from the
<CITE>IBM Dictionary of Computing</CITE>, SC20-1699.

		<TABLE CELLPADDING="3">
<TR><TD COLSPAN="2"><STRONG>A
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>accelerator
</TD><TD><P>A "shortcut" that minimizes the number of keystrokes or mouse
clicks required to complete a task.
</TD></TR><TR VALIGN="TOP"><TD><P>anchor window
</TD><TD><P>The window in which a Data Explorer session starts (either the
Visual
Program Editor or the Image window).
The window is identified by an anchor symbol
in the top left corner.
When this window is closed, the Data Explorer session ends.
</TD></TR><TR VALIGN="TOP"><TD><P>architecture
</TD><TD><P>The organizational structure of a computer system,
including hardware and software.
</TD></TR><TR VALIGN="TOP"><TD><P>array
</TD><TD><P>In Data Explorer, an array structure containing an ordered list of
data
items of the same type along with additional descriptive
information.
Arrays are either compact or irregular.
See <I>compact array, irregular array</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>assembly
</TD><TD><P>An object representing a collection of objects.
</TD></TR><TR VALIGN="TOP"><TD><P>attribute
</TD><TD><P>A characteristic of an object.
Objects can have attributes that are indexed by a string name and have
a value that is an object.
See also <I>component attribute</I>.
</TD></TR><TR><TD COLSPAN="2"><STRONG>C
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>camera
</TD><TD><P>
An object that describes the viewing parameters of an image (e.g.,
width of the viewport, viewer&#39;s location relative to the
object, and the resolution and aspect ratio of the
image).
A camera may be explicitly defined and passed as a parameter to the
Render or Display module.
It may also be implicitly defined in the use of interactive,
mouse-driven options (such as zoom or rotate) in the
Image window.
<P>
</TD></TR><TR VALIGN="TOP"><TD><P>canvas
</TD><TD><P>The area of a VPE window used in building and editing
visual programs.
</TD></TR><TR VALIGN="TOP"><TD><P>cell-centered data
</TD><TD><P>Connection-dependent data.
</TD></TR><TR VALIGN="TOP"><TD><P>clipping plane
</TD><TD><P>A plane that divides a three-dimensional object into a rendered and
an unrendered region, making the object&#39;s interior visible.
</TD></TR><TR VALIGN="TOP"><TD><P>colormap
</TD><TD><P>A map that relates colors to data values.
The colors are carried in the map&#39;s "data" component and the
data values to which each color applies
in its "positions" component.
</TD></TR><TR VALIGN="TOP"><TD><P>colormap editor
</TD><TD><P>A special tool for mapping precise colors to specified data values,
the results of which are displayed in a visual image.
</TD></TR><TR VALIGN="TOP"><TD><P>compact array
</TD><TD><P>Any of five types of compact encoding of array data:
<DL COMPACT>
<DD>constant array
<DD>mesh array
<DD>path array
<DD>product array
<DD>regular array
</DL>
</TD></TR><TR VALIGN="TOP"><TD><P>component
</TD><TD><P>A basic part of a field (such as "positions," "data,"
or "colors"); each component is indexed by a string (e.g.,
"positions"), and its value is typically an array
object (e.g., the list of position values).
See also <I>component attribute</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>component attribute
</TD><TD><P>A characteristic of a component.
Components of a field can have attributes that are indexed by a
string name and have a value that is an object.
</TD></TR><TR VALIGN="TOP"><TD><P>composite field
</TD><TD><P>A grouping of like fields for processing a single spatial entity.
See also <I>partitioned field</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>connection
</TD><TD><P>Component of an IBM Data Explorer data field that specifies how a
set of points are joined together.
Also controls interpolation.
</TD></TR><TR VALIGN="TOP"><TD><P>connection-dependent data
</TD><TD><P>Cell-centered data.
The data value is interpreted as constant throughout the connection
element.
</TD></TR><TR VALIGN="TOP"><TD><P>contour
</TD><TD><P>On a surface, a line that connects points having the same data
value (e.g., pressure, depth, temperature).
</TD></TR><TR VALIGN="TOP"><TD><P>control panel
</TD><TD><P>An IBM Data Explorer window that facilitates setting and changing
the
parameters of visual programs.
</TD></TR><TR VALIGN="TOP"><TD><P>cube
</TD><TD><P>A volumetric connection element that connects eight positions in a
data field.
</TD></TR><TR VALIGN="TOP"><TD><P>cutting plane
</TD><TD><P>An arbitrary plane, in three-dimensional space, onto which
data are mapped.
</TD></TR><TR><TD COLSPAN="2"><STRONG>D
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>data-driven interactors
</TD><TD><P>Interactors whose attributes (such as minimum and maximum) are
set by an input data field.
</TD></TR><TR VALIGN="TOP"><TD><P>Data Prompter
</TD><TD><P>An interface that enables a user to describe the format of the data
in a file.
The prompter creates a General Array Format header file that is used
by the Import module to import the data.
</TD></TR><TR VALIGN="TOP"><TD><P>dependence
</TD><TD><P>A component attribute.
One component is said to be dependent ("dep") on another if the
items in their component arrays are in one-to-one correspondence
to each other.
</TD></TR><TR VALIGN="TOP"><TD><P>dialog box
</TD><TD><P>The "window" displayed when the user selects a pull-down
option that offers or requires more detailed specification.
</TD></TR><TR VALIGN="TOP"><TD><P>display
</TD><TD><P>(1) To present information for viewing, usually on a terminal
screen or a hard-copy device.
<BR>(2) A device or medium on which information is presented,
such as a terminal screen.
<BR>(3) Deprecated term for <I>panel</I>.
</TD></TR><TR><TD COLSPAN="2"><STRONG>E
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>element
</TD><TD><P>Connection item.
</TD></TR><TR VALIGN="TOP"><TD><P>element type
</TD><TD><P>An attribute that describes the type of connection element, for
example, "cubes", "tetrahedra", or "lines".
</TD></TR><TR VALIGN="TOP"><TD><P>executive
</TD><TD><P>The component of the Data Explorer system that manages the execution
of
specified modules.
The term often refers to the entire server portion of the Data Explorer
client-server model, including the executive, modules,
and data-management components.
</TD></TR><TR><TD COLSPAN="2"><STRONG>F
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>face
</TD><TD><P>(1) Any planar surface that bounds a three-dimensional object.
<BR>(2) A polygon.
</TD></TR><TR VALIGN="TOP"><TD><P>field
</TD><TD><P>A self-contained collection of data
items.
A Data Explorer field typically consists of the data itself (the "data"
component), a set of sample points (the "positions"
component), a set of interpolation elements (the
"connections" component), and other
information as needed.
</TD></TR><TR VALIGN="TOP"><TD><P>flat shading
</TD><TD><P>A shading model in which each face of an object is shaded with a
single intensity value.
Contrast with <I>Gouraud shading</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>fork
</TD><TD><P>An operation that causes a program to branch into two or more
parallel concurrent paths.
</TD></TR><TR VALIGN="TOP"><TD><P>fork&#45;join parallelism
</TD><TD><P>A programming mechanism that supports parallel
processing:
The fork statement splits a single computation into multiple
independent computations.
The join statement recombines two or more concurrent computations
into one.
</TD></TR><TR><TD COLSPAN="2"><STRONG>G
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>general array format
</TD><TD><P>A data-importing method that uses a header file to describe the
data format of a data file.
This "format" makes it possible to import data in a variety
of formats.
</TD></TR><TR VALIGN="TOP"><TD><P>glyph
</TD><TD><P>A graphical figure used to represent values of a particular
variable.
The length, angle, or other attribute of the glyph is some function
of the value of that variable.
Each occurrence of a glyph represents a single value of the variable.
</TD></TR><TR VALIGN="TOP"><TD><P>Gouraud shading
</TD><TD><P>Also called intensity interpolation shading.
A shading model in which the intensity of values of incident
illumination on a polygon are interpolated from intensity values at
the vertices of the polygon.
Contrast with <I>flat shading</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>graphical user interface
</TD><TD><P>A set of panels and dialogs for interacting with an
application.
</TD></TR><TR VALIGN="TOP"><TD><P>group
</TD><TD><P>A collection of objects.
</TD></TR><TR><TD COLSPAN="2"><STRONG>I
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>icon
</TD><TD><P>A displayed symbol that a user can point to with a device such as a
mouse to select a particular operation or software application.
</TD></TR><TR VALIGN="TOP"><TD><P>image window
</TD><TD><P>IBM Data Explorer window that displays the image generated by a
visual
program.
Associated with the Image window are special interactors
for 3-D viewing.
</TD></TR><TR VALIGN="TOP"><TD><P>interactor
</TD><TD><P>A Data Explorer device used to manipulate data in order to change
the
visual image produced by a program.
See also <I>data-driven interactor, interactor stand-in</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>interactor stand-in
</TD><TD><P>An icon used in the VPE window to represent
an interactor.
Stand-ins are named after the type of data they generate:
<UL COMPACT>
<LI>integer
<LI>scalar
<LI>selector (outputs a value and a string)
<LI>string
<LI>value
<LI>vector
</UL>
</TD></TR><TR VALIGN="TOP"><TD><P>interpolation element
</TD><TD><P>An item in the connections component array.
Each interpolation element provides a means for interpolating data
values at locations other than the specified set of sample points.
See <I>positions component</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>invalid
</TD><TD><P>A classification of an array item (typically positions or
connections). An invalid item is not to be rendered or
realized.
</TD></TR><TR VALIGN="TOP"><TD><P>irregular array
</TD><TD><P>In contrast to a compact array, an array in which the data is
stored explicitly.
</TD></TR><TR VALIGN="TOP"><TD><P>isosurface
</TD><TD><P>A surface in three-dimensional space that connects all the points
in a data set that have the same value.
</TD></TR><TR VALIGN="TOP"><TD><P>isovalue
</TD><TD><P>The single value that characterizes each and every point
constituting an isosurface.
By default, this value is the average of all the data values in the
set being visualized.
</TD></TR><TR VALIGN="TOP"><TD><P>item
</TD><TD><P>A single piece of data in an array.
</TD></TR><TR><TD COLSPAN="2"><STRONG>J
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>join
</TD><TD><P>An operation that merges two or more computation paths.
</TD></TR><TR><TD COLSPAN="2"><STRONG>L
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>line
</TD><TD><P>An element that connects two positions in a field.
</TD></TR><TR><TD COLSPAN="2"><STRONG>M
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>macro
</TD><TD><P>In IBM Data Explorer, a sequence of modules that acts as a
functional unit
and is displayed as a single icon.
Macros can also be defined in the Data Explorer scripting
language.
</TD></TR><TR VALIGN="TOP"><TD><P>member
</TD><TD><P>An individual unit or object in a group.
A collection of members makes a group.
</TD></TR><TR VALIGN="TOP"><TD><P>menu bar
</TD><TD><P>In windows, a horizontal bar that displays the names of one or more
menus (or tasks).
When the user selects a menu, a pull-down list of options for that menu
is displayed.
</TD></TR><TR VALIGN="TOP"><TD><P>mesh array
</TD><TD><P>A compact array that encodes multidimensional regularity
of connections.
It is a product of path arrays.
In a mesh array, which positions are connected to one another is
implicitly rather than explicitly defined.
</TD></TR><TR VALIGN="TOP"><TD><P>module
</TD><TD><P>(1) In IBM Data Explorer, a primitive function, such as Isosurface.
<BR>(2) In a VPE window, the icon for a module.
<BR>(3) A program unit that is functionally discrete and identifiable
(i.e., it can be assembled, compiled, combined with other units,
and so on).
</TD></TR><TR><TD COLSPAN="2"><STRONG>N
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>navigate
</TD><TD><P>To move the camera (changing the "to" and "from" points)
around the image scene, using the mouse.
</TD></TR><TR VALIGN="TOP"><TD><P>netCDF
</TD><TD><P>Network Common Data Form.
</TD></TR><TR VALIGN="TOP"><TD><P>network
</TD><TD><P>In Data Explorer the set of tool modules, interactor stand-ins, and
connections that constitute a visual program.
In the VPE window, a network appears as a set of icons connected by
arcs.
</TD></TR><TR VALIGN="TOP"><TD><P>Network Common Data Form (netCDF)
</TD><TD><P>A data format that stores and retrieves scientific data in
self&#45;describing, multidimensional blocks (netCDF is not
a database management system, however).
netCDF is accessible with C and FORTRAN.
</TD></TR><TR VALIGN="TOP"><TD><P>normal
</TD><TD><P>(1) Perpendicular to a surface.
<BR>(2) In IBM Data Explorer, a vector that is perpendicular to a face or
surface
of an object.
A normal may depend on connections or positions.
A connection-dependent normal results in flat shading;
a position-dependent normal results in Gouraud shading.
</TD></TR><TR><TD COLSPAN="2"><STRONG>O
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>object
</TD><TD><P>In IBM Data Explorer, any discrete and identifiable entity;
specifically,
a region of global memory that contains its own type-identification
and other type-specific information.
</TD></TR><TR VALIGN="TOP"><TD><P>opacity
</TD><TD><P>The capacity of matter to prevent the transmission of
light.
For a surface, an opacity of 1 means that it is completely opaque; an
opacity of 0, that it is completely transparent.
For volume, opacity is defined as the amount of attenuation (of
light) per unit distance.
</TD></TR><TR><TD COLSPAN="2"><STRONG>P
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>page
</TD><TD><P>(1) That portion of a panel displayed by a user interface.
<BR>(2) To move back and forth through the pages of a multipage panel.
See also <I>scroll</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>palette
</TD><TD><P>A displayed grouping of available selections (such as functions,
modules, or colors) in a user-interface window.
</TD></TR><TR VALIGN="TOP"><TD><P>palindrome
</TD><TD><P>In Data Explorer, a mode of running an entire sequence, first in one
direction, then in the opposite direction.
</TD></TR><TR VALIGN="TOP"><TD><P>panel
</TD><TD><P>A formatted display of information on a display
screen.
See also <I>window</I>.
Synonymous with <I>display</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>partitioned field
</TD><TD><P>A composite field, created by partitioning a single field
into a collection of separate fields; used for parallel
processing and data-management purposes.
</TD></TR><TR VALIGN="TOP"><TD><P>path array
</TD><TD><P>A compact array that encodes linear regularity of
connections.
It is a set of <I>n</I>&#45;1 line segments, where the
<I>i</I>th line segment joins points <I>i</I>
and <I>i</I> &#43; 1.
</TD></TR><TR VALIGN="TOP"><TD><P>pixel
</TD><TD><P>Picture element.
In computer graphics, the smallest element of a display surface that
can be independently assigned color and intensity.
</TD></TR><TR VALIGN="TOP"><TD><P>polygon
</TD><TD><P>(1) Any multisided planar figure.
<BR>(2) A face of a three-dimensional object.
</TD></TR><TR VALIGN="TOP"><TD><P>position-dependent data
</TD><TD><P>Data that are in one-to-one correspondence with positions.
</TD></TR><TR VALIGN="TOP"><TD><P>positions component
</TD><TD><P>A component that consists of a set of dimensional points in a
field.
</TD></TR><TR VALIGN="TOP"><TD><P>probe
</TD><TD><P>A list of one or more vectors that represent points in a
graphical image.
Probes can be used with Data Explorer tools that accept vectors as input (such
as ClipPlane and Streamline) or to control the view of an image.
</TD></TR><TR VALIGN="TOP"><TD><P>product array
</TD><TD><P>A compact array that encodes multidimensional positional
regularity.
It is the set of points obtained by summing one point from each
of the terms in all possible combinations.
In the simplest case, each term is a regular array.
</TD></TR><TR VALIGN="TOP"><TD><P>pull-down
</TD><TD><P>In windows, the list of options displayed when a task is selected
from the menu bar.
</TD></TR><TR><TD COLSPAN="2"><STRONG>Q
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>quad
</TD><TD><P>An element that connects four positions in a field.
</TD></TR><TR><TD COLSPAN="2"><STRONG>R
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>rank
</TD><TD><P>The number of dimensions in an array.
Rank zero corresponds to
scalars (e.g., the number 3).
Rank one corresponds
to vectors (e.g, <I>&#91;1.5&nbsp;3.7&#93;</I>
and <I>&#91;2.9&nbsp;4.0&nbsp;6.0&#93;</I>).
Rank two corresponds to matrices or rank-two
tensors (e.g., the matrix
<I>&#91;&#91;1&nbsp;3&nbsp;8&#93;&#91;5&nbsp;7&nbsp;2&#93;&#91;1&nbsp;0&nbsp;1&#
93;&#93;</I>).
Higher ranks correspond to higher-order tensors.
See also <I>shape</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>realization
</TD><TD><P>A description of how raw data is to be represented in terms of
boundaries, surfaces, transparency, color, and other graphical,
image, and geometric characteristics.
</TD></TR><TR VALIGN="TOP"><TD><P>reference
</TD><TD><P>A component attribute.
One component is said to <I>refer to</I> another ("ref")
if the items in the first array are integer indices into
the second array.
The connections component references the positions component.
</TD></TR><TR VALIGN="TOP"><TD><P>regular array
</TD><TD><P>A compact array that is a set of <I>n</I> points lying on a
line, with constant spacing between them, which can represent
one-dimensional regular positions.
</TD></TR><TR VALIGN="TOP"><TD><P>rendering
</TD><TD><P>The generation of an image from some representation of an object,
such as a surface, or from volumetric information.
</TD></TR><TR VALIGN="TOP"><TD><P>ribbon
</TD><TD><P>A figure derived from lines (e.g., from streamlines and
streaklines).
Ribbons may twist to indicate vorticity.
</TD></TR><TR><TD COLSPAN="2"><STRONG>S
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>sample point
</TD><TD><P>A point that represents user data.
Data is interpolated between sample points by interpolation
elements (connections).
</TD></TR><TR VALIGN="TOP"><TD><P>scalar
</TD><TD><P>A non-vector value characterized by a single, real number.
</TD></TR><TR VALIGN="TOP"><TD><P>scatter data
</TD><TD><P>A collection of sample points without connections.
</TD></TR><TR VALIGN="TOP"><TD><P>screen
</TD><TD><P>An illuminated display surface (e.g., the display surface
of a CRT or plasma panel).
</TD></TR><TR VALIGN="TOP"><TD><P>scripting language
</TD><TD><P>The IBM Data Explorer command language.
Used for writing visual programs, to manage the execution of modules,
and to invoke visualization functions.
</TD></TR><TR VALIGN="TOP"><TD><P>scroll
</TD><TD><P>To move all or part of the display image vertically
or horizontally to display
data that cannot be observed in a single display image.
</TD></TR><TR VALIGN="TOP"><TD><P>secondary window
</TD><TD><P>Any window generated by another window.
A secondary window always appears on top of its parent window
and is automatically minimized or closed when the parent
window is minimized or closed.
Synonymous with <I>child window</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>sequencer
</TD><TD><P>An IBM Data Explorer tool for creating "animated" sequences of
images.
</TD></TR><TR VALIGN="TOP"><TD><P>series
</TD><TD><P>In IBM Data Explorer, used to represent a single field sampled
across
some parameter (e.g., a simulation of a CMOS device across a
temperature range).
Members of a series have a position.
A copy of the position is found in the "series position"
attribute.
</TD></TR><TR VALIGN="TOP"><TD><P>shape
</TD><TD><P>A list of the dimensions of a structure (the list contains nothing
for scalars, one entry for vectors, two for rank-two tensors,
and so on).
See also <I>rank</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>shared
</TD><TD><P>A term used to indicate the availability of a resource for use
by more than one program at the same time.
</TD></TR><TR VALIGN="TOP"><TD><P>specular reflection
</TD><TD><P>A reflection from a shiny object.
</TD></TR><TR VALIGN="TOP"><TD><P>stand-in
</TD><TD><P>See <I>interactor stand-in</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>streaklines
</TD><TD><P>Lines that represent the path of particles in a changing vector
field.
Also called rakes.
</TD></TR><TR VALIGN="TOP"><TD><P>streamlines
</TD><TD><P>Lines that represent the path of particles in a vector field at
a particular time.
Also called flow lines.
</TD></TR><TR><TD COLSPAN="2"><STRONG>T
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>task
</TD><TD><P>A basic unit of work to be accomplished by a computer.
</TD></TR><TR VALIGN="TOP"><TD><P>tetrahedron
</TD><TD><P>A volumetric connection element that connects four positions in
a field.
</TD></TR><TR VALIGN="TOP"><TD><P>tool
</TD><TD><P>In IBM Data Explorer, a general term for any icon used to build a
visual program (specifically, module, macro, or interactor
stand-in).
</TD></TR><TR VALIGN="TOP"><TD><P>triangle
</TD><TD><P>A connection element that connects three points in a field.
</TD></TR><TR VALIGN="TOP"><TD><P>tube
</TD><TD><P>A surface centered on a deriving line (e.g., a streamline or
streakline).
Tubes may twist to indicate vorticity.
</TD></TR><TR><TD COLSPAN="2"><STRONG>U
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>user
</TD><TD><P>Anyone who uses the services of a computer system.
See also <I>user display station</I>.
</TD></TR><TR><TD COLSPAN="2"><STRONG>V
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>value
</TD><TD><P>An instance of an attribute (for example, "blue" as the
value of the attribute "color").
</TD></TR><TR VALIGN="TOP"><TD><P>vector
</TD><TD><P>A quantity characterized by more than one component.
</TD></TR><TR VALIGN="TOP"><TD><P>visual program
</TD><TD><P>A user-specified interconnected set of Data Explorer modules that
performs
a sequence of operations on data and typically produces an image
as output.
</TD></TR><TR VALIGN="TOP"><TD><P>vertex
</TD><TD><P>One of the positions that define a connection element.
</TD></TR><TR VALIGN="TOP"><TD><P>visual program editor
</TD><TD><P>IBM Data Explorer window used to create and edit visual programs and
macros.
See also <I>canvas</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>volume
</TD><TD><P>The amount of three&#45;dimensional space occupied by an object
or substance (measured in cubic units).
To be distinguished from an object&#39;s surface, which is a
mathematical abstraction.
</TD></TR><TR VALIGN="TOP"><TD><P>volume rendering
</TD><TD><P>A technique for using color and opacity to visualize all the data
in a 3-dimensional data set.
The internal details visualized may be physical (such as the structure
of a machine part) or they may be other characteristics (such as fluid
flow, temperature, or stress).
</TD></TR><TR VALIGN="TOP"><TD><P>vorticity
</TD><TD><P>Mathematically defined as the curl of a velocity field.
A particle in a velocity field with nonzero vorticity will rotate.
</TD></TR><TR><TD COLSPAN="2"><STRONG>W
</STRONG>
					<P></TD></TR><TR VALIGN="TOP"><TD><P>window
</TD><TD><P>On a visual display terminal,
information in a framed area on a panel that
overlies part of the panel.
See also <I>anchor window,
primary window, secondary window</I>.
</TD></TR><TR VALIGN="TOP"><TD><P>wireframe
</TD><TD><P>Connected lines that represent a surface.
</TD></TR></TABLE>
		<P>
		<HR>
		<DIV ALIGN="center">
			<P><A HREF="../allguide.htm"><IMG SRC="../images/foot-fc.gif" WIDTH="94" HEIGHT="18" BORDER="0" ALT="Full Contents"></A> <A HREF="../qikguide.htm"><IMG SRC="../images/foot-qs.gif" WIDTH="94" HEIGHT="18" BORDER="0" ALT="QuickStart Guide"></A> <A HREF="../usrguide.htm"><IMG SRC="../images/foot-ug.gif" WIDTH="94" HEIGHT="18" BORDER="0" ALT="User's Guide"></A> <A HREF="../refguide.htm"><IMG SRC="../images/foot-ur.gif" WIDTH="94" HEIGHT="18" BORDER="0" ALT="User's Reference"></A></P>
		</DIV>
		<DIV ALIGN="center">
			<P><FONT SIZE="-1">[ <A HREF="http://www.research.ibm.com/dx">OpenDX Home at IBM</A>&nbsp;|&nbsp;<A HREF="http://www.opendx.org/">OpenDX.org</A>&nbsp;] </FONT></P>
			<P></P>
		</DIV>
	</BODY></HTML>
